(1) Field of the Invention
This invention relates to new compounds which mimic insect sex pheromone and are used to disrupt sexual communication between the insects.
(2) Description of the Prior Art
Mating communication in moths and other insects can be disrupted by evaporating physiologically large quantities of the major sex pheromone component or components into the air within or over a crop or commodity. This technique is often termed as air permeation and the disruptants are chemicals that have an effect when evaporated into the air at many points surrounding the pheromone emitter.
The disruption of mating communication via air permeation has also been accomplished with non-pheromonal chemicals having structural properties similar to the pheromone components of the target species. The rice stem borer, Chilo suppressalis (Walker), the corn earworm, Heliothis zea (Boddie), and the tobacco budworm, H. virescens (F.) utilize (Z)-11-hexedecenal (HDA) as a major component of the females' sex pheromone. Two groups [E. R. Mitchell, M. Jacobson and A. J. Baumhover, Environ. Entomol. 4, 577-79 (1975) and P. S. Beevor, Dr. R. Hall, B. F. Nesbitt, V. A. Dyck, G. Arida, P. C. Lippold and Oloumi-Sadeghi, Bull. Entomol. Res. 67, 439 (1977).] have shown that (Z)-9-tetradecen-1-ol formate (TDF), a structurally related analog of this aldehyde, is an effective disruptant of mating communication in air permeation trials against these species. Another group [S. Tatsuki, and K. Kanno, pp. 313-325 in E. R. Mitchell, ed., Management of Insect Pests with Semiochemicals: Concepts and Practice. Plenum Press, New York. (1981)] has discovered that an olefin, (Z)-5-hexadecene, will disrupt the mating communication of C. suppressalis. This olefin also inhibits the response of C. suppressalis males to pheromone-releasing females in a trap when it is evaporated from the same locus (trap). Some chemicals act as both communication disruptants and inhibitors of attraction; however, this is not always the case. [See G. H. L. Rothschild, Entomol. Exp. and Appl. 17, 294-302 (1974)].
Greenblatt et al. (1976) showed that (Z)-14-methyl-8-hexadecenal was extremely potent at low treatments, releasing attraction in 50% of male Trogoderma variable at 10.sup.-8 g. This was the most active of the synthesized components of the pheromone blend of this species, and showed less activity against T. glabrum, T. inclusum and T. simplex.
Aldehyde pheromones tend to polymerize when stored in bulk, and present longevity problems in the field due to air oxidation and photosensitivity. Therefore, alternative materials with improved behavioral effects, greater stability and reduced cost are of great interest for use in insect control.